Bistable behavior of the nitrogen impurity in SiC nanoclusters

Nanoscale ◽  
2020 ◽  
Vol 12 (21) ◽  
pp. 11536-11555
Author(s):  
T. L. Petrenko ◽  
V. P. Bryksa ◽  
T. T. Petrenko
Keyword(s):  
Effective Mass ◽  
Bistable Behavior ◽  
Bound Polaron ◽  
Nitrogen Impurity

Bistable behavior and coexistence of effective mass, small bound polaron and DX-like states of the nitrogen impurity in SiC nanoclusters.

EFFECTIVE MASS OF STRONG-COUPLED BOUND POLARON IN AN ASYMMETRIC QUANTUM DOT INDUCED WITH RASHBA EFFECT

2011 ◽  
Vol 10 (03) ◽  
pp. 501-505 ◽  
Author(s):  
ZHIXIN LI ◽  
JUAN XIAO ◽  
AIYONG LIU ◽  
JINGLIN XIAO
Keyword(s):  
Quantum Dot ◽  
Effective Mass ◽  
Operator Method ◽  
Transformation Method ◽  
Rashba Effect ◽  
Linear Combination Operator ◽  
Polaron Model ◽  
Bound Polaron ◽  
Asymmetric Quantum Dot ◽  
Asymmetric Quantum

In this paper, on the basis of Huybrechs' strong-coupled polaron model, the Tokuda-modified linear-combination operator method and the unitary transformation method are used to study the properties of the strong-coupled bound polaron considering the influence of Rashba effect, which is brought by the spin-orbit (SO) interaction, in an asymmetric quantum dot (QD). The expression for the effective mass of the polaron as functions of the transverse and longitudinal bound strengths, velocity, vibration frequency, and the bound potential has been derived. After a simple numerical calculation on the RbCl crystal, we found that the total effective mass of the bound polaron is composed of three parts. The interaction between the orbit and the spin with different directions has different effects on the effective mass of the bound polaron.

Bound polaron in a narrow-band polar crystal

1993 ◽  
Vol 71 (11-12) ◽  
pp. 493-500
Author(s):  
Y. Lépine ◽  
O. Schönborn
Keyword(s):  
Effective Mass ◽  
Ground State ◽  
Narrow Band ◽  
Wave Functions ◽  
Phonon Coupling ◽  
Polar Crystal ◽  
Bound Polaron ◽  
Narrow Bandwidth ◽  
Electron Phonon Coupling ◽  
Shallow Impurities

The ground-state energy of a bound polaron in a narrow-band polar crystal (such as a metal oxide) is studied using variational wave functions. We use a Fröhlich-type Hamiltonian on which the effective mass approximation has not been effected and in which a Debye cutoff is made on the phonon wave vectors. The wave functions that are used are general enough to allow the existence of a band state and of a self-trapped state and are reliable in the nonadiabatic limit. We find that three ground states are possible for this system. First, for small electron–phonon coupling, moderate bandwidth, and shallow impurities, the usual effective-mass hydrogenic ground state is found. For a narrow bandwidth and a deep defect, a collapsed state is predicted in which the polaron coincides with the position of the defect. Finally, for moderate electron–phonon coupling, narrow bandwidth, and a very weak defect, a self-trapped polaron in a hydrogenic state is predicted. Our conclusions are presented as asymptotic expansions and as phase diagrams indicating the values of the parameters for which each phase can be found.

Bound-polaron model of effective-mass binding energies in GaN

1998 ◽  
Vol 57 (15) ◽  
pp. 8951-8956 ◽  
Author(s):  
Stephen A. McGill ◽  
Ke Cao ◽  
W. Beall Fowler ◽  
Gary G. DeLeo
Keyword(s):  
Effective Mass ◽  
Binding Energies ◽  
Polaron Model ◽  
Bound Polaron

Adiabatic large polarons in anisotropic molecular crystals

2011 ◽  
Vol 35 (1) ◽  
pp. 15-27
Author(s):  
Zoran Ivić ◽  
Željko Pržulj
Keyword(s):  
Energy Transfer ◽  
Effective Mass ◽  
Molecular Crystals ◽  
Single Chain ◽  
Proper Understanding ◽  
One Dimensional ◽  
Interchain Coupling ◽  
Large Polaron ◽  
The One

Adiabatic large polarons in anisotropic molecular crystals We study the large polaron whose motion is confined to a single chain in a system composed of the collection of parallel molecular chains embedded in threedimensional lattice. It is found that the interchain coupling has a significant impact on the large polaron characteristics. In particular, its radius is quite larger while its effective mass is considerably lighter than that estimated within the one-dimensional models. We believe that our findings should be taken into account for the proper understanding of the possible role of large polarons in the charge and energy transfer in quasi-one-dimensional substances.

Three-terminal bistable switches in effective-mass superlattices

1988 ◽  
Vol 24 (1) ◽  
pp. 64-65 ◽  
Author(s):  
A. Aishima ◽  
Y. Fukushima
Keyword(s):  
Effective Mass

Effective masses in a dense fermion background — Applied to neutrinos, dark matter and dark energy

2014 ◽  
Vol 29 (21) ◽  
pp. 1444010
Author(s):  
Bruce H. J. McKellar ◽  
T. J. Goldman ◽  
G. J. Stephenson
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Scalar Field ◽  
Effective Mass ◽  
Negative Pressure ◽  
Expectation Value ◽  
Effective Masses ◽  
Neutrino Astrophysics

If fermions interact with a scalar field, and there are many fermions present the scalar field may develop an expectation value and generate an effective mass for the fermions. This can lead to the formation of fermion clusters, which could be relevant for neutrino astrophysics and for dark matter astrophysics. Because this system may exhibit negative pressure, it also leads to a model of dark energy.

scholarly journals Lac Operon Boolean Models: Dynamical Robustness and Alternative Improvements

Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 600 ◽  
Author(s):  
Marco Montalva-Medel ◽  
Thomas Ledger ◽  
Gonzalo A. Ruz ◽  
Eric Goles
Keyword(s):  
Escherichia Coli ◽  
Limit Cycles ◽  
The Other ◽  
Lac Operon ◽  
Boolean Models ◽  
Bistable Behavior

In Veliz-Cuba and Stigler 2011, Boolean models were proposed for the lac operon in Escherichia coli capable of reproducing the operon being OFF, ON and bistable for three (low, medium and high) and two (low and high) parameters, representing the concentration ranges of lactose and glucose, respectively. Of these 6 possible combinations of parameters, 5 produce results that match with the biological experiments of Ozbudak et al., 2004. In the remaining one, the models predict the operon being OFF while biological experiments show a bistable behavior. In this paper, we first explore the robustness of two such models in the sense of how much its attractors change against any deterministic update schedule. We prove mathematically that, in cases where there is no bistability, all the dynamics in both models lack limit cycles while, when bistability appears, one model presents 30% of its dynamics with limit cycles while the other only 23%. Secondly, we propose two alternative improvements consisting of biologically supported modifications; one in which both models match with Ozbudak et al., 2004 in all 6 combinations of parameters and, the other one, where we increase the number of parameters to 9, matching in all these cases with the biological experiments of Ozbudak et al., 2004.

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